<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1, user-scalable=no">
    <meta http-equiv="X-UA-Compatible" content="ie=edge,chrome=1">
    <meta name="author" content="HYL">
    <title></title>
    <style>
        ul{
            width:600px;
             display: flex; 
             justify-content: space-between;    
             list-style: none; 
            margin:200px auto; 
            padding: 0;    
        }
        li{
            /* widows: 118px; */
            border:1px solid black;
            cursor: pointer;
            /* background-color:gray; */
            width: 100px;
            height: 30px;
        }
         /* li:hover{
            border:1px solid red;
            border-bottom:none;
        }  */
       .a{
            border:1px solid red;
        }
    </style>
</head>
<body>
        <ul>
            <li>不分期</li>
            <li>$1896x3期</li>
            <li>$948x6期</li>
            <li>$488.2x12</li>
            <li>$265.44x24</li>
        </ul>
<script src="Jquery.js"></script>
</body>
</html>
<script>
    $('li').click(function(){        
        // $(this).addClass('a').siblings().removeClass('a');
        $(this).toggleClass('a').siblings().removeClass('a');
    });
    
</script>